Air pump



8 0O 11 9 l R E T. s O F E 5 April 22 1924.

AIR PUMP Filed May 11 1923 ATTORNEY atented Apr. 22, 1924;

EDWIN a rosran, or anemia, TEXAS.

: runs.

Application filed-Kay 11, 1923. ficrial No. 638,208.

1 particularly to such as are used in the infiation of pneumatic-tiresand tubes for vehicle wheels, and the chief object is to provide aconvenient, portable and efficient airpump of the cylinder and pistontype, operable by hand, wherein cylinders and piston heads are soassociated and arranged as to practically afford a pump having triplecylinder capacity in a size no larger than a one-cylinder pump. Otherobjectsand advantages will appear in the course of this specification.

In the drawing:

Figure 1 1s a longitudinal section'through the pump.

Figure 2 is an elevation of the pump.

The invention consists of a suitable base.

or foot-piece 1, formed with an air recess 2 communicating througha duct3 with the air delivery pipe 4. The foot-piece 1 is formed ,with anannular shoulder 5 upon which is seated a base washer 6. Into thefoot-piece 1 are detachably mounted a relatively large stationaryair-cylinder 7 having a threaded connection 8 with the foot-piece, and asmall central air-tube 9 having a threaded connection 10 through thebase Washer 6. The tube 9 is thus given direct communication with pipe4. Through the washer 6 is formed an air port 11, at the under side ofwhich is seated a ball-valve 12 held to its seat by a coil spring 13seated over a pin 14. Within the cylinder 7 is slidingly mounted areciprocating air-cylinder 15, its outer diameter being slightly lessthan the inner diameter of the cylinder 7. so as to leave a smallintervening air space 16 between the two cylinders. An annular pistonhead 17 is mounted at the lower end of the inner reciprocating cylinder15, the same encircling the air tube 9 and having a downwardly cuppedflexible ring 18 supported at its under side by a metal washer 19. Alateral air duct 20 connects the air space 16 with the interior 21 ofthe cylinder 15 above the piston 17 and the upper mouth of this duct iscovered by a ball valve 22 in a cage 23 for admitting air into thereciprocating cylinder on its downward stroke.

At the upper end of the air tube 9 are mounted two flexible rings 24 and25, they being spaced apart and cupped toward each other as shown, toform an intervening twoway air trap 26, designed to collect thecompressed a1r from above it or'belowit, from either end of the cylinder15, as that cylinder is moved up and down in the outer cylnder 7, anddirect the said compressed air through a port 27 in the end of thetube15,

down through thesaid tube and out through the delivery pipe 4. Theleather rings 24 and 25 are properly supported at each side by'metalwashers 28. An annular cap 42 encircles the top of the outer cylinder 7and the body of the reciprocating cylinder and is detachably joined tothe outer cylinder by a threaded connection 29. Below the cap 28 anumber of air ports 30 are pierced through the outer cylinder 7 and leadair into the space 16, whence on the downward stroke of the innercylinder 15 the air'fiows through the duct 20 up into space 21 of thecylinder 15. At the top of the reciprocating cylinder 15 is detachablymounted an annular cap 31 having a threaded connection 32 with thecylinder, and the'handle 33 is secured to this top cap by means of atubular bolt 34 extended through the handle and having a threadedconnection at 35 through the said cap 31. A valve cap 36 is detachablymounted at the lower end of the tubular bolt 34 by a threaded connection37 and a ball valve 38 is placed within this cap and seats against thelowerend of the tubular bolt 34. An air duct 39 leads down through thevalve cap 36, thus admitting air through the tubular bolt 34 into theupper end of the cylinder 15 on the upward stroke of the said cylinderand closingupwardl against its seat on the downward stroke. nut 40 hasthreaded connection at 41 with the upper end of the tubular bolt 34 andafi'ords means for locking the handle in place. On the downward strokeof the cylinder 15 air is forced into the pipe 4 both by the piston 17carrying the downwardly cupped leather ring 18 and by the lower andupwardly cupped lower leather ring 24 at the top of the tube 9, thislatter stream of air being directed through the port 27 and down throughthe tube 9. At the same time 'from the spirit of the invention, so asto:

air feeds through the ports 30, air space 16 and duct 20 up into thespace 21 of the cglinder 15. Then on the upward stroke of t e cylinder15 this air is trapped by the downwardly cupped upper leather ring 25and directed through the port 27 into the tube 9. Thus the pump forcestwo separate streams of air into the pipe/1 on the downward stroke, andone stream or air into the 4 on the upward stroke.

. ile I have herein described a certain specific manner and method ofconstructing and assembling the elements of my invcntion," it isunderstood that I may vary from the same in minor details, not departingbest construct a practical device for the purpose intended, as definedin the appended claims. I p

Iclaim:

1. An .air pump of. the kind described, comprising a; foot-piece havingan air recess and duct adapted for the connection of a deliverypipe, therecess having an annularshoulder around its. mouth; abase washer seatedon the shoulder; a downwardly opening valve leading through said basewasher;

a relatively large stationary air. cylinder; mounted on the base washerover" the air recess of the foot-piece and having air ports near itsupper end; a relatively small air tube mounted through the base washer,said tube having an air port in its upper end; a. reciprocating aircylinder mounted within the stationary air cylinder with an air.

space between the two; an annular piston head at the lower end ofthereciprocating cglinder and encircling the central air tube, t e

flexible ring and an air. duct connecting the interior of thereciprocating cylinder above.

its piston with the air space between the two cylinders; a valve at theupper mouth ofthe duct for admitting air into the reciprocating cylinderon its downward stroke; an airtrap at the upper end of the central airtube; consisting of two flexible rings'sp'aced apart and cupped towardeach other to direct air down through the said port in the end of thetube; an annular cap at the top of the stationary cylinder andencircling the body of the reciprocating cylinder; a handle at the topof the reciprocating cylinder hav-' ing an air duct leading therethroughinto the said cylinder; and a valve set in said duct so as to admit'airinto the cylinder on its upward stroke. Y

2. An air pump of the kind described, comprising a foot-piece having anenclosed air recess and duct for connecting a delivery pi e; arelatively large stationary air cyl-v in' er on the foot-piece overthe'air' recess; a downwardly opening valve leadingfrom the lower end ofthe. said cylinder into the air recess of the foot-piece; a relativelyeach other; and a handle at the to piston having aadownwardly cuppedarses connecting through an upwardly opening. I

valve, the interiorof the reciprocating cylinder with theair spacebetween the ders; an air trap at the upper end o the central air tube,including two spaced flexible rings covering the upper-port of thecentral air tubeand being cupped toward I of the reciprocating cylinderhaving a va vecontroiled air duct therethrough 'into the saidcl'ylindenthe valve being set 'to admit air on t on ward stroke. 3-.

air P p r thekind described, p nga foot-piece with an enclosed airrecess and an outwardly o ening duct; a, stationary air cyhn'der on te-foot piece.; a

downwardly opening valve leadin from the cylin. into the air recess ofthev cot-piece;

an air tube within the cylinder, on the foot piece, and communicatingdirectly with the ort atits;

recess, the .tube havin an air upper end ajreciprocatmgair cylinderwithin the stationary cylinder, there being as.

air spacebetween the two; a piston on the lower end of thereciprocating,

c inder adapted to .force air downwardly through the-stationary cylinderand having a lateral valve-controlled duct into the space between thecylinders; an air-trap at the upper end-of the air tube adapted todirectair into the tube through its port on .both the downward and upwardmovement of the reciprocating cylinder; and a handle at the upper .endof 1 the reciprocating cylinder havinga valve-controlled air inlet intothe said cylinder; all of said valves being set 'to force air throughthe said outwardly openingductof the foot-piece on both the downward andupward stroke or the reciprocating cylinder, a

4. An air pump as described, comprising a recessed foot-p1ec'e having anoutwardly directed air duct; a stationary air cylinder" on thefoot-piece; an air escape valve conneoting the .ower end of the aircylinder I with the recess in the foot-piece; an air tube with a port.at its u per end, centrally mounted on the foot-piece and within thestationary cylinder, and opening directly into the recess of thefoot-piece; a reciprocating air cylinder within the stationary cylinder,there being an intervening air space; a p ston'head on the lower end ofthe reciprocating cylinder adapted to force air downwardly and having avalve controlled'duct into the space between the cylinders; an air-trapat the upper end of the air tube adapted to direct air into the tubethrough its said port, on both movements on the reciprocating cylinder;and a handle at the upper end of the reciprocating cylinder having avalve-controlled inlet to the cylinder, all of the said valves being setto make the pump operative on both movements of the reciprocatingcylinder.

5. An air pump as described, comprising a recessed foot-piece having anoutlet from the recess; a stationary air cylinder on the foot-piece; avalve leading from the lower end of the air cylinder into the recessedfoot-piece; an air tube centrally fixed on the foot-piece, within thestationary cylinder and openin into the recess of the footpiece, thesaid tube having an air port at its upper end and an air trap adapted toentrap air into the tube from above or below; a reciprocating aircylinder within the stationary cylinder with the air space between thecylinders, the reciprocating cylinder fittin over the air trap of thecentral tube an having an annular piston, operative downwardly, fittingthe stationary cylinder and encircling the central air tube, the pistonhaving an air duct into the space between the cylinders; a handle at theupper end of the reciprocating cylinder, the handle having an air ductinto the cylinder; and valves seated in all the said ducts to make thepump operative on both movements of the reciprocating cylinder.

6. In an air pump of the kind described and including a foot-piecehaving a recess and an outlet therefrom; a stationary air cylinder andan air tube centrally placed therein, both being mounted on thefootpiece and communlcating throu h air ducts with the recess thereof,and t e air tube having an air port thereinto at its upper end and atwo-way air trap; an outwardly directed valve mounted in the ductconnecting the stationary air cylinder with the recess of thefoot-piece; and a reciprocating cylinder within the stationary cylinderwith space between the two, the reciprocating cylinder havin an annularpiston encircling the air tube, tting the stationary tube and o erativedownwardly only therein, the sai piston having an air duct into thespace between the cylinders and having an air duct at its upper endcommunicating with the outer air 3 and valves controlling all of thesaid communicatingair ducts to make the pump operatlve on bothreciprocal movements of the reclprocatmg cylinder.

EDWIN E.'FOSTER.

Witnesses:

S. P. Fnoonn, F. R. Rosrox.

